This paper examines several issues regarding deception in advertising. Some generally accepted definitions are considered and found to be inadequate. An alternative definition is proposed for legal/regulatory purposes and is related to a suggested definition of the term deception as it is used in everyday language. Based upon these definitions, suggestions are offered for detecting and regulating deception in advertising. This paper additionally considers the grounds for the generally held but largely unquestioned assumption that deceptive advertising is unethical. It is argued that deceptive advertising can be shown to be morally objectionable, on the weak assumption that it is prima facie wrong to harm others. Finally, the implications of this analysis with respect to current regulation of deceptive advertising by the FTC are considered.